package pers.ree.demo.base;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

public class HashMapDemo {

    public static void main(String[] args) {
        HashMap<String, String> map = new HashMap<>();

        map.put("a", null);
        map.put("b", null);
        map.put("c", null);

        Iterator<Map.Entry<String, String>> iterator = map.entrySet().iterator();
        while (iterator.hasNext()) {
            Map.Entry<String, String> entry = iterator.next();
            System.out.println(123);
        }
    }
}
